Bug 2496726

Summary: CVE-2026-54431 liboauth2: liboauth2: DPoP verifier accepts malformed proof with private key material [fedora-all]
Product: [Fedora] Fedora Reporter: Jeremy Choi <jechoi>
Component: liboauth2Assignee: Alexander Bokovoy <abokovoy>
Status: NEW --- QA Contact:
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Priority: medium    
Version: rawhideCC: abokovoy
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
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Whiteboard: {"flaws": ["7eb830f9-d8ef-40ca-a028-b9cb78412f9a"]}
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Bug Blocks: 2496464    

Description Jeremy Choi 2026-07-03 02:20:19 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

In liboauth2 the Demonstrating Proof-of-Possession (DPoP) verifier accepts a proof whose JSON Web Key (jwk) header contains private key material. RFC 9449 section 4.3 step 7 requires the verifier to reject such a proof but oauth2_token_verify() function returns success for a malformed DPoP proof that embeds the private Elliptic Curve (EC) key in the header.

This issue was fixed in version 2.3.0